A causal relationship between appendicular lean mass and atrial fibrillation: A two sample Mendelian randomization study

BACKGROUND AND AIM

The relationship between appendicular lean mass (ALM) and most cardiovascular events has been established, but the direct association between ALM and atrial fibrillation (AF) remains uncertain.

METHODS AND RESULTS

Herein, we identified 494 single-nucleotide polymorphisms (SNPs) strongly associated with ALM as instrumental variables (P < 5E-8) based on a genome-wide association study (GWAS) with 450,243 European participants. Then, we employed five Mendelian randomization (MR) analysis methods to investigate the causal relationship between ALM and AF. All results indicated a causal relationship between ALM and AF, among Inverse variance weighted (P = 8.44E-15, odds ratio [OR]: 1.16, 95 % confidence interval [CI]: 1.114-1.198). Furthermore, we performed a sensitivity analysis, which revealed no evidence of pleiotropy (egger_intercept = 0.000089, P = 0.965) or heterogeneity (MR Egger, Q Value = 0.980; Inverse variance weighted, Q Value = 0.927). The leave-one-out method demonstrates that individual SNPs have no driven impact on the whole causal relationship. Multivariable MR analysis indicates that, after excluding the influence of hypertension and coronary heart disease, a causal relationship between ALM and AF still exists (P = 7.74E-40, OR 95 %CI: 1.389 (1.323-1.458)). Importantly, the Radial MR framework analysis and Robust Adjusted Profile Score (RAPS) further exhibit the robustness of this causal relationship.

CONCLUSION

A strong association between ALM and AF was confirmed, and high ALM is a risk factor for AF.

Appendicular lean mass and the risk of stroke and Alzheimer's disease: a mendelian randomization study

BACKGROUND

Appendicular lean mass (ALM) is a good predictive biomarker for sarcopenia. And previous studies have reported the association between ALM and stroke or Alzheimer's disease (AD), however, the causal relationship is still unclear, The purpose of this study was to evaluate whether genetically predicted ALM is causally associated with the risk of stroke and AD by performing Mendelian randomization (MR) analyses.

METHODS

A two-sample MR study was designed. Genetic variants associated with the ALM were obtained from a large genome-wide association study (GWAS) and utilized as instrumental variables (IVs). Summary-level data for stroke and AD were generated from the corresponding GWASs. We used random-effect inverse-variance weighted (IVW) as the main method for estimating causal effects, complemented by several sensitivity analyses, including the weighted median, MR-Egger, and MR-pleiotropy residual sum and outlier (MR-PRESSO) methods. Multivariable analysis was further conducted to adjust for confounding factors, including body mass index (BMI), type 2 diabetes mellitus (T2DM), low density lipoprotein-C (LDL-C), and atrial fibrillation (AF).

RESULTS

The present MR study indicated significant inverse associations of genetically predicted ALM with any ischemic stroke ([AIS], odds ratio [OR], 0.93; 95% confidence interval [CI], 0.89-0.97; P = 0.002) and AD (OR, 090; 95% CI 0.85-0.96; P = 0.001). Regarding the subtypes of AIS, genetically predicted ALM was related to the risk of large artery stroke ([LAS], OR, 0.86; 95% CI 0.77-0.95; P = 0.005) and small vessel stroke ([SVS], OR, 0.80; 95% CI 0.73-0.89; P < 0.001). Regarding multivariable MR analysis, ALM retained the stable effect on AIS when adjusting for BMI, LDL-C, and AF, while a suggestive association was observed after adjusting for T2DM. And the estimated effect of ALM on LAS was significant after adjustment for BMI and AF, while a suggestive association was found after adjusting for T2DM and LDL-C. Besides, the estimated effects of ALM were still significant on SVS and AD after adjustment for BMI, T2DM, LDL-C, and AF.

CONCLUSIONS

The two-sample MR analysis indicated that genetically predicted ALM was negatively related to AIS and AD. And the subgroup analysis of AIS revealed a negative causal effect of genetically predicted ALM on LAS or SVS. Future studies are required to further investigate the underlying mechanisms.

Causal associations between sarcopenia-related traits and intervertebral disc degeneration: a two-sample mendelian randomization analysis

BACKGROUND

Sarcopenia (SP) and intervertebral disc degeneration (IVDD) have a higher incidence in the elderly population. Previous studies have indicated a potential association between SP and IVDD. The objective of this study is to elucidate the potential causal relationship between sarcopenia-related traits and IVDD through Two-sample Mendelian randomization (MR) analysis.

METHODS

We utilized a genome-wide association study conducted on the European population to collect aggregated data on sarcopenia and IVDD. Inverse variance weighting was primarily employed, supplemented by MR Egger, weighted median, simple model, and weighted model methods. Additionally, sensitivity analysis was performed to assess the robustness of the findings.

RESULTS

Appendicular lean mass is positively associated with "Other intervertebral disc disorders" (OIDD) and "Prolapsed or slipped disc" (POSD) (OIDD: p = 0.002, OR = 1.120; POSD: p < 0.001, OR = 1.003), while grip strength (GS) is positively associated with POSD (left: p = 0.004, OR = 1.008; right: p < 0.001, OR = 1.010). It is worth mentioning that walking pace has significant causal relationship with "Low back pain" (LBP), "Lower back pain or/and sciatica" (LBPOAS), "Sciatica with lumbago" (SWL) and OIDD (LBP: p < 0.001, OR = 0.204; LBPOAS: p < 0.001, OR = 0.278; SWL: p = 0.003, OR = 0.249; OIDD: p < 0.001, OR = 0.256).

CONCLUSION

The present study revealed the causal relationship between SP-related traits and IVDD and recommended to prevent and treat sarcopenia as a means of preventing IVDD in clinic practice.

The causal relationship of human blood metabolites with the components of Sarcopenia: a two-sample Mendelian randomization analysis

BACKGROUND

Sarcopenia is a progressive loss of muscle mass and function. Since skeletal muscle plays a critical role in metabolic homeostasis, identifying the relationship of blood metabolites with sarcopenia components would help understand the etiology of sarcopenia.

METHODS

A two-sample Mendelian randomization study was conducted to examine the causal relationship of blood metabolites with the components of sarcopenia. Summary genetic association data for 309 known metabolites were obtained from the Twins UK cohort and KORA F4 study (7824 participants). The summary statistics for sarcopenia components [hand grip strength (HGS), walking pace (WP), and appendicular lean mass (ALM)] were obtained from the IEU Open GWAS project (461,089 participants). The inverse variance weighted method was used, and the MR-Egger, weighted median, and MR-PRESSO were used for the sensitivity analyses. Metabolic pathways analysis was further performed.

RESULTS

Fifty-four metabolites associated with sarcopenia components were selected from 275 known metabolites pool. Metabolites that are causally linked to the sarcopenia components were mainly enriched in amino sugar and nucleotide sugar metabolism, galactose metabolism, fructose and mannose metabolism, carnitine synthesis, and biotin metabolism. The associations of pentadecanoate (15:0) with ALM, and 3-dehydrocarnitine and isovalerylcarnitine with HGS were significant after Bonferroni correction with a threshold of P < 1.82 × 10- 4 (0.05/275). Meanwhile, the association of hyodeoxycholate and glycine with the right HGS, and androsterone sulfate with ALM were significant in the sensitivity analyses.

CONCLUSION

Blood metabolites from different metabolism pathways were causally related to the components of sarcopenia. These findings might benefit the understanding of the biological mechanisms of sarcopenia and targeted drugs development for muscle health.

Metabolome-Wide Mendelian Randomization Assessing the Causal Relationship Between Blood Metabolites and Sarcopenia-Related Traits

Sarcopenia is among the most common musculoskeletal illnesses, yet its underlying biochemical mechanisms remain incompletely understood. In this study, we used Mendelian randomization (MR) to investigate the causal relationship between the genetically determined blood metabolites and sarcopenia, with the overall objective of identifying likely molecular pathways for sarcopenia. We used 2-sample MR to investigate the effects of blood metabolites on sarcopenia-related traits. 452 metabolites were exposure, and 3 sarcopenia-related traits as the outcomes: handgrip strength, appendicular lean mass, and walking pace. The inverse-variance weighted (IVW) causal estimates were determined. For sensitivity analysis, methods such as MR-Egger regression, the weighted median, the weighted mode, and the heterogeneity test were used. Additionally, for complementation, we performed replication, meta-analysis, and metabolic pathway analyses. Candidate biomarkers were defined by meeting one of the following criteria: (1) significant metabolites are defined as pIVW < pBonferroni [1.11 × 10-4 (.05/452)]; (2) strong metabolites are defined as 4 MR methods p < .05; and (3) suggestive metabolites are defined as passing sensitivity analysis. Three metabolites (creatine, 1-arachidonoylglycerophosphocholine, and pentadecanoate [15:0]) with significant causality, 3 metabolites (glycine, 1-arachidonoylglycerophosphocholine, and epiandrosterone sulfate) with strong causality, and 25 metabolites (including leucylleucin, pyruvic acid, etc.) with suggestive causality were associated with sarcopenia-related traits. After further replication analyses and meta-analysis, these metabolites maintained substantial effects on sarcopenia-related traits. We additionally identified 14 important sarcopenia-related trait metabolic pathways. By combining metabolomics with genomics, these candidate metabolites and metabolic pathways identified in our study may provide new clues regarding the mechanisms underlying sarcopenia.

The effect of body compartments on lung function in childhood and adolescence

BACKGROUND

There is an association between body composition and lung function, assessed by spirometry, but the effects of body compartments on static lung volumes and its changes during lung growth remain to be explored. We aimed to investigate the association of appendicular lean mass, reflecting skeletal muscle mass, and fat mass on forced and static lung function measures in childhood and adolescence.

METHODS

In total, 1489 children and adolescents (6-18 years) of the observational, longitudinal (first and second visit within 4 years), general population-based LEAD study have been investigated. The association of appendicular lean mass and fat mass indices (ALMI and FMI; assessed by dual-energy X-ray absorptiometry) on lung function by spirometry (FEV1, FVC) and body plethysmography (TLC, RV, FRC) was investigated cross-sectionally. Longitudinal associations between lung function and body compartment changes between the two visits were analyzed.

FINDINGS

The ALMI is positively associated with FEV1, FVC, and TLC. Contrary, FMI is inversely associated with lung function measures including FRC and RV. During the phase of lung growth, higher gain in muscle mass is associated with higher increases of FVC and TLC.

INTERPRETATION

This study demonstrates the different effects of muscle and fat mass on forced expiratory and static lung volumes. Achieving and maintaining muscle mass in childhood and adolescence might become an important preventive strategy for lung health in adulthood.

Identification of molecular mediators of renal sarcopenia risk: a mendelian randomization analysis

BACKGROUND

Observational studies have shown an association between reduced renal function and the risk of sarcopenia. However, the causal relationship and the underlying biological mechanisms remain uncertain. Using a Mendelian randomization (MR) framework, we investigated the causal role of 27 hypothetical risk mediators, including metabolites, hormones, inflammation, and stress traits, on the risk of sarcopenia.

METHODS

Instrumental variables (IVs) to proxy renal function were identified by selecting single nucleotide polymorphisms (SNPs) reliably associated with creatinine and cystatin C-based glomerular filtration rate (GFR) in CKDGen summary data. IVs for putative risk traits and sarcopenia traits were constructed from relevant genome-wide association studies (GWAS). MR estimated effects were obtained using an inverse-variance weighted effects model, and various sensitivity analyses were performed. The mediating role of hypothetical risk factors in the relationship between GFR and sarcopenia was assessed through multivariate MR.

RESULTS

Genetically predicted reduced GFRcrea was associated with higher odds of appendicular lean mass (ALM) (odds ratio (OR): 0.64, 95% confidence interval (CI) 0.37 to 0.68) and grip strength (OR: 0.67; 95% CI 0.58 to 0.78). Likewise, GFRcys highlighted a causal relationship with ALM (OR: 0.52; 95% CI 0.42 to 0.65) and grip strength (OR: 0.66; 95% CI 0.59 to 0.74). Both estimated GFR (eGFR) were negatively associated with IGF-1, IL-16, 25(OH)D, triglycerides (range of effect size per standard deviation: -0.81 to -0.30), and positively correlated with HDL cholesterol (0.62, 0.31). There was a positive correlation between IGF-1, fasting insulin and ALM as well as grip strength (OR range: 1.04-1.67) and a negative correlation between serum CRP and ALM (OR: 0.95) as well as grip strength (OR: 0.98). Additionally, genetically predicted IL-1β (OR: 0.95) and total cholesterol (OR: 0.96) were negatively associated with ALM. We found evidence that IGF-1 mediates the relationship between eGFR and risk for muscle mass and strength.

CONCLUSIONS

This MR study provides insight into the potential causal mechanisms between renal function and the risk of sarcopenia and proposes IGF-1 as a potential target for the prevention of renal sarcopenia.

Depression and sarcopenia-related traits: A Mendelian randomization study

BACKGROUND

Observational studies have suggested that depression is associated with sarcopenia. However, the causal relationship between depression and sarcopenia remains unclear.

AIM

To investigate the causal relationship between depression and sarcopenia.

METHODS

We performed a Mendelian randomization (MR) analysis to identify the bidirectional relationship between depression and sarcopenia-related traits. Summary-level data and independent variants used as instrumental variables came from large genome-wide association studies of depression (414055 cases and 892299 controls), of appendicular lean mass (ALM, 450243 participants), and of hand grip strength (exposure: 360000 participants; outcome: 334925 participants).

RESULTS

We identified a negative association of depression with lower ALM [odds ratio (OR): 0.932, 95% confidence interval (95%CI): 0.889-0.979, P = 0.005]. In the reverse MR analysis, we also observed an inverse association of hand grip strength with depression (OR: 0.200, 95%CI: 0.108-0.370, P < 0.001). Similar results were obtained in sensitivity analyses.

CONCLUSION

Depression was causally related to decreased muscle mass, and declined muscle strength might lead to a higher risk of depression.

Nutritional Interventions: Dietary Protein Needs and Influences on Skeletal Muscle of Older Adults

BACKGROUND

This narrative review describes foundational and emerging evidence of how dietary protein intakes may influence muscle-related attributes of older adults.

METHODS

PubMed was used to identify pertinent research.

RESULTS

Among medically stable older adults, protein intakes below the recommended dietary allowance (RDA) (0.8 g/kg body weight [BW]/d) exacerbate age-related reductions in muscle size, quality, and function. Dietary patterns with total protein intakes at or moderately above the RDA, including one or preferably more meals containing sufficient dietary protein to maximize protein anabolism, promote muscle size and function. Some observational studies suggest protein intakes from 1.0 to 1.6 g/kg BW/d may promote greater muscle strength and function more so than muscle size. Experimental findings from randomized controlled feeding trials indicate protein intakes greater than the RDA (averaging ~1.3 g/kg BW/d) do not influence indices of lean body mass or muscle and physical functions with non-stressed conditions, but positively influence changes in lean body mass with purposeful catabolic (energy restriction) or anabolic (resistance exercise training) stressors. Among older adults with diagnosed medical conditions or acute illness, specialized protein or amino acid supplements that stimulate muscle protein synthesis and improve protein nutritional status may attenuate the loss of muscle mass and function and improve survival of malnourished patients. Observational studies favor animal versus plant protein sources for sarcopenia-related parameters.

CONCLUSIONS

Quantity, quality, and patterning of dietary protein consumed by older adults with varied metabolic states, and hormonal and health status influence the nutritional needs and therapeutic use of protein to support muscle size and function.

Chest X-ray-based opportunistic screening of sarcopenia using deep learning

BACKGROUND

Early detection and management of sarcopenia is of clinical importance. We aimed to develop a chest X-ray-based deep learning model to predict presence of sarcopenia.

METHODS

Data of participants who visited osteoporosis clinic at Severance Hospital, Seoul, South Korea, between January 2020 and June 2021 were used as derivation cohort as split to train, validation and test set (65:15:20). A community-based older adults cohort (KURE) was used as external test set. Sarcopenia was defined based on Asian Working Group 2019 guideline. A deep learning model was trained to predict appendicular lean mass (ALM), handgrip strength (HGS) and chair rise test performance from chest X-ray images; then the machine learning model (SARC-CXR score) was built using the age, sex, body mass index and chest X-ray predicted muscle parameters along with estimation uncertainty values.

RESULTS

Mean age of the derivation cohort (n = 926; women n = 700, 76%; sarcopenia n = 141, 15%) and the external test (n = 149; women n = 95, 64%; sarcopenia n = 18, 12%) cohort was 61.4 and 71.6 years, respectively. In the internal test set (a hold-out set, n = 189, from the derivation cohort) and the external test set (n = 149), the concordance correlation coefficient for ALM prediction was 0.80 and 0.76, with an average difference of 0.18 ± 2.71 and 0.21 ± 2.28, respectively. Gradient-weight class activation mapping for deep neural network models to predict ALM and HGS commonly showed highly weight pixel values at bilateral lung fields and part of the cardiac contour. SARC-CXR score showed good discriminatory performance for sarcopenia in both internal test set [area under the receiver-operating characteristics curve (AUROC) 0.813, area under the precision-recall curve (AUPRC) 0.380, sensitivity 0.844, specificity 0.739, F1-score 0.540] and external test set (AUROC 0.780, AUPRC 0.440, sensitivity 0.611, specificity 0.855, F1-score 0.458). Among SARC-CXR model features, predicted low ALM from chest X-ray was the most important predictor of sarcopenia based on SHapley Additive exPlanations values. Higher estimation uncertainty of HGS contributed to elevate the predicted risk of sarcopenia. In internal test set, SARC-CXR score showed better discriminatory performance than SARC-F score (AUROC 0.813 vs. 0.691, P = 0.029).

CONCLUSIONS

Chest X-ray-based deep leaning model improved detection of sarcopenia, which merits further investigation.

Metabolic-associated fatty liver disease is associated with low muscle mass and strength in patients with chronic hepatitis B

BACKGROUND

Although the prognostic relevance of sarcopenia has been increasingly recognised in the context of liver disease, there is a paucity of data evaluating body composition in patients with chronic hepatitis B (CHB). Beyond virus-related factors, nutritional and metabolic aspects can be associated with skeletal muscle abnormalities in these patients and should not be disregarded.

AIM

To evaluate the association between components of sarcopenia and demographic, clinical, lifestyle, nutritional, and biochemical variables in CHB patients.

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to assess muscle mass by quantifying appendicular lean mass (ALM) adjusted for body mass index (ALM_BMI). Muscle function was evaluated by hand grip strength (HGS) and the timed up and go test. Metabolic-associated fatty liver disease (MAFLD) was defined according to the criteria proposed by an international expert panel. A body shape index and the International Physical Activity Questionnaire were used to assess central obesity and physical activity level, respectively.

RESULTS

This cross-sectional study included 105 CHB outpatients followed at the tertiary care ambulatory centre (mean age, 48.5 ± 12.0 years; 58.1% males; 76.2% without cirrhosis; 23.8% with compensated cirrhosis). The DXA-derived fat mass percentage was inversely correlated with the ALM_BMI (r = - 0.87) and HGS (r = - 0.63). In the multivariable analysis, MAFLD, sedentarism and central obesity were positively and independently associated with low ALM_BMI. MAFLD and central obesity were independently associated with low HGS.

CONCLUSION

MAFLD and central obesity were associated with low muscle mass and strength in patients with chronic hepatitis B, independent of the liver disease stage.

The effect of disease-modifying anti-rheumatic drugs on skeletal muscle mass in rheumatoid arthritis patients: a systematic review with meta-analysis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease, characterized by chronic and systemic inflammation. Besides, it is known that RA patients may present several comorbidities, such as sarcopenia, a condition where patients present both muscle mass and muscle quality impairment. RA treatment is mostly pharmacological and consists in controlling systemic inflammation and disease activity. Despite that, the effect of pharmacological treatment on sarcopenia is not well characterized.

OBJECTIVE

To summarize the effects of disease-modifying anti-rheumatic drugs (DMARDs) on skeletal muscle tissue in rheumatoid arthritis (RA) patients.

METHODS

A systematic review of randomized clinical trials and observational studies was conducted using MEDLINE, Embase, Cochrane Library, and Web of Science. We selected studies with rheumatoid arthritis patients treated with disease-modifying anti-rheumatic drugs (DMARDs) that analyzed muscle mass parameters such as lean mass and appendicular lean mass. Methodological quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Standardized mean difference (SMD) and 95% confidence intervals (CI) were set. A meta-analysis of observational studies was performed using the R software, and we considered significant statistics when p < 0.05.

RESULTS

Nine studies were included in this systematic review. In the meta-analysis, DMARD treatment had no positive difference (p = 0.60) in lean mass. In the same way, in the appendicular lean mass parameter, our results showed that DMARDs did not have changes between baseline and post-treatment analysis (p = 0.93).

CONCLUSION

There is no evidence of a significant effect of DMARD therapy, either synthetic or biological, on muscle mass. However, this association should be investigated with more studies.

Estimation of Whole-Body and Appendicular Lean Mass from Spine and Hip Dual Energy X-ray Absorptiometry: A Cross-Sectional Study

Whole-body dual X-ray absorptiometry (DXA) accurately measures lean mass but is not routinely used in clinical practice. Hip and spine DXA are used in the diagnosis of osteoporosis, and with the common co-occurrence of sarcopenia with osteoporosis, regional DXA scans provide an opportunity for assessment of lean mass. The aim of this study is to develop predictive equations for the estimation of whole-body lean mass (WBLM), appendicular lean mass (ALM) and whole-body fat mass (WBFM) from regional DXA scans. A total of 2427 participants (ages 20-96 year; 57.7% men) from the Geelong Osteoporosis Study who underwent both regional and whole-body DXA were included in the analysis. Using forward stepwise multivariable linear regression, percentage fat (spine%fat, hip%fat) values from lumbar spine and femoral neck DXA were used in combination with clinical data to develop and validate equations for the estimation of WBLM, WBFM and ALM. Mean age was 53.5 year (± 19.2), weight 78.2 kg (± 15.4), height 169.6 cm (± 9.4), WBLM 50.4 kg (± 11.1), ALM 22.8 kg (± 5.4) and WBFM 24.3 kg (± 10.4). Spine%fat (r = 0.21) and hip%fat (r = - 0.34) were correlated with whole-body lean mass (p < 0.001). Final predictive equations included age, sex, weight, height, spine%fat, and hip%fat and possessed high predictive value (Adj R² 0.91-0.94, RMSE 1.60-2.84 kg). K-fold cross-validation methods produced median root mean square error (RMSE) ranging from 1.59 to 2.81 kg for the three models. Regional DXA scans of the spine and hip can be used to estimate whole-body and appendicular lean mass, to assist in the identification of low muscle mass.

Adherence to Mediterranean diet and its associations with circulating cytokines, musculoskeletal health and incident falls in community-dwelling older men: The Concord Health and Ageing in Men Project

BACKGROUND & AIMS

Mediterranean dietary patterns may exert favourable effects on various health conditions. This study aimed to determine associations of adherence to Mediterranean diet as well as its components, with circulating cytokine levels, musculoskeletal health and incident falls in community-dwelling older men.

METHODS

Seven hundred ninety-four (794) community-dwelling men with mean age 81.1 ± 4.5 years, who participated in the five-year follow-up of the Concord Health and Ageing in Men Project (CHAMP) were included in the cross-sectional analysis, and 616 attended follow-up three years later. Adherence to Mediterranean diet was assessed using MEDI-LITE (literature-derived Mediterranean diet) score which was obtained using a validated diet history questionnaire. Twenty-four evaluable circulating cytokines were analyzed using Bio-Plex Pro Human Cytokine 27-plex Assay kit. Appendicular lean mass (ALM) and bone mineral density (BMD) were measured using dual-energy x-ray absorptiometry (DXA). Three-year changes in gait speed and hand grip strength were assessed by walking a 6-m course and using a dynamometer respectively and analyzed using linear mixed-effects models. Incident falls over three years were determined through telephone interviews every four months. Multivariable linear regression was utilized to determine the cross-sectional associations between MEDI-LITE scores and circulating cytokines, bone mineral density, ALM, and ALM_BMI. Linear mixed-effects models were performed to estimate associations between MEDI-LITE scores and three-year change in hand grip strength and gait speed while negative binomial regression was applied to estimate associations between MEDI-LITE scores and three-year incident falls as well as associations between each MEDI-LITE component and three-year incident falls. Adjustments for multiple comparisons were performed using Benjamini-Hochberg adjustment for multiple testing.

RESULTS

A higher MEDI-LITE score, indicating greater adherence to Mediterranean diet, was associated with higher appendicular lean mass adjusted for body mass index (ALM_BMI) (β: 0.004 kg; 95% CI: 0.000, 0.008), and lower incident falls rates (IRR: 0.94; 95% CI: 0.89, 0.99). Higher consumption of monounsaturated fatty acids (IRR: 0.76; 95% CI: 0.59, 0.98) and monounsaturated fatty acids to saturated fatty acids ratio (IRR: 0.72; 95% CI: 0.57, 0.90) were associated with 24%, and 28% lower falls risk in older men respectively. MEDI-LITE scores were not associated with BMD or physical function parameters.

CONCLUSIONS

Adherence to a Mediterranean diet is associated with higher ALM_BMI, and fewer falls in community-dwelling older men. Monounsaturated and saturated fatty acids were the most important contributors to the association between Mediterranean diet and falls risk.

Bioelectrical impedance analysis as an alternative to dual-energy x-ray absorptiometry in the assessment of fat mass and appendicular lean mass in patients with obesity

OBJECTIVE

Obesity is a challenge for bioelectrical impedance analysis (BIA) estimations of skeletal muscle and fat mass (FM), and none of the equations used for appendicular lean mass (ALM) have been developed for people with obesity. By using different equations and proposing a new equation, this study aimed to assess the estimation of FM and ALM using BIA compared with dual-energy x-ray absorptiometry (DXA) as a reference method in a cohort of people with severe obesity.

METHODS

This cross-sectional study compared a multifrequency BIA (TANITA MC-780A) versus DXA for body composition assessment in adult patients with severe obesity (body mass index [BMI] of >35 kg/m²). Comparisons between measured (DXA) and predicted (BIA) data for FM and ALM were performed using the original proprietary equations of the device and the equations proposed by Kyle, Sergi, and Yamada. Bland-Altman plots were drawn to evaluate the agreement between DXA and BIA, calculating bias and limits of agreement (LOA). Reliability was analyzed using intraclass correlation coefficient (ICC). Stepwise multiple regression analysis was used to derive a new equation to predict ALM in patients with obesity and was validated in a subsample of our cohort.

RESULTS

In this study, 115 patients (72.4% women) with severe obesity (mean BMI of 46.1 [5.2] kg/m²) were included (mean age 43.5 [8.6] y). FM_DXA was 61.4 (10.1) kg, FM_BIA was 57.9 (10.3) kg, and ICC was 0.925 (P < 0.001). Bias was -3.4 (4.4) kg (-5.2%), and LOA was -14.0, +7.3 kg. Using the proprietary equations, ALMDXA was 21.8 (4.7) kg and ALMBIA was 29.0 (6.8) kg with an ICC 0.868, bias +7.3 (4.0) kg (+34.1%) and LOA -0.5, +15.1. When applying other equations for ALM, the ICC for Sergi, et al. was 0.880, the ICC for Kyle, et al. was 0.891, and the best ICC estimation for Yamada, et al. was 0.914 (P < 0.001). Bias was +2.8 (2.8), +4.1 (2.9), and +2.7 (2.8) kg, respectively. The best-fitting regression equation to predict ALM_DXA in our population derived from a development cohort (n = 77) was: ALM = 13.861 + (0.259 x H2/Z) - (0.085 x age) - (3.983 x sex [0 = men; 1 = women]). When applied to our validation cohort (n = 38), the ICC was 0.864, and the bias was the lowest compared with the rest of the equations +0.3 (+0.5) kg (+2.7%) LOA -5.4, +6.0 kg.

CONCLUSION

BIA using multifrequency BIA in people with obesity is reliable enough for the estimation of FM, with good correlation and low bias to DXA. Regarding the estimation of ALM, BIA showed a good correlation with DXA, although it overestimated ALM, especially when proprietary equations were used. The use of equations developed using the same device improved the prediction, and our new equation showed a low bias for ALM.

Associations of coffee drinking with physical performance in the oldest-old community-dwelling men The Helsinki Businessmen Study (HBS)

Background

Habitual coffee drinking has been associated with lower risk of various chronic diseases linked to poor physical performance.

Objective

We explored cross-sectional associations between coffee consumption and physical performance among oldest-old community-dwelling men in the Helsinki Businessmen Study (HBS).

Methods

A random sample of HBS survivors (n = 126, mean age 87 years) attended a clinic visit in 2017/2018, including measurements of body composition, physical performance [Short Physical Performance Battery (SPPB)], and cognition. Coffee consumption was retrieved from 3-day food diaries.

Results

Coffee consumption was positively associated with higher gait speed (p = 0.003), SPPB score (p = 0.035), and chair rise points (p = 0.043). Association of coffee with gait speed remained after adjustment for age, waist circumference, physical activity, pulse rate, and high-sensitivity C-reactive protein.

Conclusion

Higher coffee consumption was independently associated with better physical performance reflected as faster gait speed in oldest-old men.

Precision and Effects of a Small Meal on DXA-Derived Visceral Adipose Tissue, Appendicular Lean Mass, and Other Body Composition Estimates In Nonobese Elderly Men

BACKGROUND

Information on precision errors and the least significant change (LSC) of dual energy X-ray absorptiometry (DXA)-derived body composition estimates is scarce, particularly for the appendicular lean mass (ALM) and appendicular lean mass index (ALMI). Overnight fasting is recommended for body composition measurements but has not been well tolerated by some elderly patients. This study aimed to establish precision errors and LSC values of body composition estimates in all regions-including visceral adipose tissue (VAT) and ALM-and the ALMI to assess the effect of a small meal on body composition and to estimate the changes it incurred.

METHODOLOGY

Our institutional review board approved the study protocol. Altogether, 36 non-obese men aged ≥60 years, having given written informed consent, underwent body composition assessment after fasting overnight except for water. They underwent DXA scans three times, each time with repositioning (to simulate the clinical setting), the last after consuming a standardized meal (210-250 g and 200 cc of water).

RESULTS

Precision errors and LSC values of DXA-derived body composition estimates in these elderly men tended to be higher than those in reports on younger subjects. Coefficients of variation (CVs (%)) of total bone mass (Tb.BMC) and total lean mass (Tb.LM) were <1%, whereas those of total fat mass (Tb.FM) and total %fat mass (Tb.%FM) were <2%, with LSCs of 45.8 g, 706.52 g, 731.4 g, and 1.15%, respectively. The CVs (LSC) of VAT, ALM, and ALMI were 8.9% (150.65 g), 0.93% (501 g), and 0.94% (0.19), respectively. After meal consumption, the mean changes in Tb.FM, Tb.BMC, and Tb.LM were -100, -8.2, and 440 g, respectively.

CONCLUSIONS

Effects of a small meal on most parameters were trivial, including those for VAT, ALM, and ALMI, where changes were not statistically significant. None exceeded the LSC of ALM and ALMI, suggesting that a small meal is allowable before these measurements.

Association between physical activity patterns and sarcopenia in Arab men

Objective

In this study, we aimed to examine the association between physical activity patterns and sarcopenia in Arab men.

Methods

This cross-sectional study included 363 men (47.7 ± 15.4 years). We analyzed appendicular lean mass (ALM), handgrip strength test, and physical activity levels. ALM divided by height (meters) squared was calculated (ALM/Ht 2 ), and participants with −1 and −2 standard deviations below the sex-specific mean for Saudi young adults were considered to have sarcopenia class I and class II, respectively. Independent t-tests, analysis of variance, and Mann–Whitney U tests were performed to determine mean and median differences.

Results

We observed a significant difference between participants with and without sarcopenia in moderate-to-vigorous physical activity (MVPA); the correlation between ALM/H2 and MVPA was borderline significant. With a 1-hour/week increase in MVPA, ALM/Ht 2 increased by 0.30 kg/m2. Total and ALM, handgrip strength, and MVPA were significantly lower in participants age >60 years; fat mass and waist circumference were unchanged as compared with middle-aged participants.

Conclusions

We identified an association between time spent in recreational MVPA and lean muscle mass among Arab men. Future studies should examine the role of MVPA training programs on muscle mass and strength in older men.

Methodological Issues and the Impact of Age Stratification on the Proportion of Participants with Low Appendicular Lean Mass When Adjusting for Height and Fat Mass Using Linear Regression: Results from the Canadian Longitudinal Study on Aging

BACKGROUND

Using residual values calculated from models regressing appendicular lean mass on fat mass and height is one of several suggested strategies for adjusting appendicular lean mass for body size when measuring sarcopenia. However, special consideration is required when using this technique in different subgroups in order to capture the correct individuals as sarcopenic.

OBJECTIVES

To provide guidance about how to conduct stratified analyses for the regression adjustment technique using age groups as an example.

DESIGN

Cross-sectional study.

SETTING

Data collected at baseline (2012-2015) for the Canadian Longitudinal Study on Aging.

PARTICIPANTS

Community dwelling participants of European descent aged 45 to 85 years (n=25,399).

MEASUREMENTS

Appendicular lean mass, height, and weight were measured. Sex-specific residuals were calculated in participants before and after stratifying participants by age group (45-54, 55-64, 65-74, 75-85 years). Cut offs corresponding to the sex-specific 20th percentile residual values in participants ≥65 years were determined first in the residuals calculated in all participants and residuals calculated in only those aged ≥65 years. For each set of cut offs, the percentage of age and sex-stratified participants with low appendicular lean mass were compared for the residuals calculated in all participants and the residuals calculated after stratifying by age.

RESULTS

In 12,622 males and 12,737 females, regardless of the cut off used, the percentage of participants with low appendicular lean mass decreased with age when residuals were calculated after age stratification. When the residuals were calculated in all participants, the percentage of participants with sarcopenia increased from the youngest to the oldest age groups.

CONCLUSIONS

Sex-specific residuals in all participants should be calculated prior to stratifying the sample by age group, or other stratification variables, for the purposes of developing appendicular lean mass cut offs or subgroup analyses.

Implications of Race and Ethnicity in Sarcopenia US National Prevalence of Sarcopenia by Muscle Mass, Strength, and Function Indices

Sarcopenia prevalence varies widely by definitions and populations, which led to the creation of new criteria by the Sarcopenia Definitions and Outcomes Consortium. Yet, the degree to which sarcopenia prevalence varies according to these criteria across race and ethnic groups in the U.S. population needs further investigation. We estimated the US national prevalence of sarcopenia using different indices among adults aged 50-80 years across race and ethnicity groups utilizing data from the National Health and Nutrition Examination Surveys (NHANES: 1999-2002 and 2011-2014). Sarcopenia was defined by appendicular lean mass divided by body mass index (ALM/BMI), grip strength, and gait speed. For each index the following samples were constructed: grip strength (NHANES 2011-2014: N=4,615), gait speed (NHANES 1999-2002: N=3,448) and ALM/BMI (NHANES 1999-2002: N=3,448) among adults aged 50-80 years. Sarcopenia prevalence varied by race/ethnicity: NH-Whites (11.2-24.3%), Hispanics (21.9-36.0%), NH-Blacks (4.4-27.7%), and Asians/others (18.5-35.7%). Based on the multivariable models, compared to NH-Whites, NH-Blacks were less likely to have sarcopenia by ALM/BMI (OR=0.26, 95%CI: 0.18-0.39), and more likely by gait speed (OR=3.90, 95% CI: 3.00-5.06) with no difference by grip strength (OR=0.96, 95%CI: 0.75-1.24). While, Hispanics and Asians/others were more likely to have sarcopenia by grip strength, gait speed, and ALM/BMI (ORs=2.15-3.21) compared to NH-Whites. This study suggests the need for inclusion of race/ethnicity related criteria in sarcopenia definitions. Future investigations could determine whether this discrepancy between race/ethnicity across sarcopenia indices, particularly in NH-Blacks, is partly due to either muscle mass or functional changes with aging.

Comparison of the associations between appendicular lean mass adjustment methods and cardiometabolic factors

BACKGROUND AND AIMS

To compare the cross-sectional and longitudinal associations between appendicular lean mass (ALM) and cardiometabolic risk factors according to body-size adjustment methods and the contributions of genetic and/or environmental factors to the correlations between those traits.

METHODS AND RESULTS

Regression coefficients per sex-specific 1 standard deviation in bodyweight (wt), body mass index (BMI), or height-squared (ht²) adjusted ALM (assessed using a dual-energy X-ray absorptiometer (DXA) and a bioelectrical impedance analyzer (BIA) at baseline)/changes in these indices (assessed using BIA) were compared in terms of their associations with blood pressure (BP), lipid profiles, and insulin resistance profiles in 2655 participants for cross-sectional analysis and 332 participants for longitudinal analysis (follow-up time, 32.2 ± 7.9 months). A bivariate genetic analysis of the genetic/environmental cross-trait correlations was conducted to determine their cross-sectional relationships. After adjusting for sociodemographic factors, health behaviors, and BMI in the analysis for ALM/ht², ALM/wt and ALM/BMI had favorable associations with all cardiometabolic risk factors, while ALM/ht² had favorable associations with some risk factors. In longitudinal associations, changes in ALM/wt and ALM/BMI had inverse associations with increments of lipid profiles, insulin, and homeostasis model assessment of insulin resistance (HOMA), while change in ALM/ht² did not have associations with increments of cardiometabolic risk factors. ALM/ht² had genetic correlations with seven of nine risk factors; ALM/wt and ALM/BMI had correlations with three and one risk factors, respectively.

CONCLUSION

ALM/wt and ALM/BMI are better indicators for cardiometabolic risk factors; genetic factors may contribute more to the correlations between ALM/ht² and those traits.

Associations of protein source, distribution and healthy dietary pattern with appendicular lean mass in oldest-old men: the Helsinki Businessmen Study (HBS)

PURPOSE

We explored how food and dietary intakes, protein daily distribution and source are associated with appendicular lean mass (ALM)/m² of the oldest-old community-dwelling men.

METHODS

Cross-sectional analyses of Helsinki Businessmen Study (HBS, mean age 87 years) participants who came to clinic visit in 2017/2018. Nutritional status, physical performance and fasting blood samples were measured. Food and dietary intakes were retrieved from 3-day food diaries. Body composition was measured and appendicular lean mass (ALM) per m² was dichotomized as ALM/m² < 7 kg/m² and ≥ 7 kg/m². Differences between lower and higher ALM were analyzed using t test or Mann-Whitney U test. Analysis of covariance was used to investigate independent associations with ALM/m².

RESULTS

Random sample of 130 participants took part in the medical examinations, 126 returned food diaries, and 102 underwent DXA-scan. ALM/m² was associated with total protein (p = 0.033), animal protein (p = 0.043) and meat protein (p = 0.033) intakes. Protein distribution between daily meals differed at lunch; those with higher ALM/m² ate more protein (p = .047) at lunch. Consumption of fruits, vegetables (p = 0.022) and meat (p = 0.006) was associated with ALM/m².

CONCLUSION

Protein intake, source and distribution as well fruit and vegetable intakes were associated with higher ALM in oldest-old men.

STUDY REGISTRATION

The study is registered with ClinicalTrials.gov identifier: NCT02526082.

Low lean mass and chemotherapy toxicity risk in the elderly: the Fraction study protocol

Background

Half of cancer cases occur in patients aged 70 and above. Majority of older patients are eligible for chemotherapy but evidence for treating this population is sparse and severe toxicities affect more than half of them. Determining prognostic biomarkers able to predict poor chemotherapy tolerance remains one of the major issues in geriatric oncology. Ageing is associated with body composition changes (increase of fat mass and loss of lean mass) independently of weight-loss. Previous studies suggest that body composition parameters (particularly muscle mass) may predict poor chemotherapy tolerance. However, studies specifically including older adults on this subject remain sparse and the majority of them study body composition based on computed tomography (CT) scanner (axial L3 section) muscle mass estimation. This method is to date not validated in elderly cancer patients.

Methods

This trial (Fraction) will evaluate the discriminative ability of appendicular lean mass measured by dual-energy X-ray absorptiometry (DXA) to predict severe toxicity incidence in older cancer-patients treated with first-line chemotherapy. DXA is considered the gold standard in body composition assessment in older adults.

Patient’s aged ≥70 diagnosed with solid neoplasms or lymphomas at a locally advanced or metastatic stage treated for first-line chemotherapy were recruited. Patients completed a pre-chemotherapy assessment that recorded socio-demographics, tumor/treatment variables, laboratory test results, geriatric assessment variables (function, comorbidity, cognition, social support and nutritional status), oncological risk scores and body composition with DXA. Appendicular lean mass was standardized using evidence based international criteria. Participants underwent short follow-up geriatric assessments within the first 3 months, 6 months and a year after inclusion. Grade 3 to 5 chemotherapy-related toxicities, as defined by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) were assessed at each chemotherapy cycle.

Discussion

The finding that body composition is associated with poor tolerance of chemotherapy could lead to consider these parameters as well as improve current decision-making algorithms when treating older adults.

Trial registration

ClinicalTrials.gov Identifier: NCT02806154 registered on October 2016.

Diagnostic Value of Mid-Thigh and Mid-Calf Bone, Muscle, and Fat Mass in Osteosarcopenia: A Pilot Study

Osteosarcopenia is defined as the concomitant occurrence of osteoporosis and sarcopenia. Current lack of consensus on sarcopenia definitions, combined with the low sensitivity and specificity of screening methodologies, has resulted in varying prevalences of sarcopenia, and consequently osteosarcopenia diagnosis. Previous research indicates that mid-thigh is a potential surrogate region for the assessment of bone, muscle, and fat mass in a single, efficient and low-radiation dual x-ray absorptiometry (DXA) scan. We hypothesized that muscle and bone mass measurements in the mid-thigh region can be used to evaluate bone and muscle health and function. A retrospective study was conducted on community-dwelling older subjects (> 65 y.o., n = 260) who were at risk of falls and fractures. Mid-thigh and mid-calf bone, lean muscle, and fat masses, as well as their association with muscle function, falls, and fractures were compared against conventional measures (hip/spine bone, appendicular lean, and gynoid/android fat masses). Mid-thigh bone, lean, and fat masses showed strong correlation with conventional measures. Mid-thigh lean mass showed similar associations with grip strength, gait speed, and timed up and go (TUG) test as appendicular lean mass. Appendicular, mid-thigh and mid-calf lean masses corrected for body mass index (BMI) showed stronger associations than when corrected for height². None of the indices were associated with fractures; but fat mass was invariably associated with falls. Those with falls and fractures history had lower bone and muscle mass at mid-thigh. Mid-thigh is a potential new surrogate to study bone, muscle, and fat mass in older people, with comparable ability in predicting muscle performance and falls.

Normative Data for Lean Mass Using FNIH Criteria in an Australian Setting

Recommendations from the FNIH Sarcopenia Project are that appendicular lean mass (ALM, kg) adjusted for body mass index (BMI, kg/m²) be used for identifying low lean mass, with ALM/BMI cutpoints of < 0.789 m² for men and < 0.512 m² for women. We report normative ALM/BMI values for Australian adults, and compare the performance of cutpoints derived from reference values for this population with FNIH values for identifying low lean mass. Body composition was measured by DXA (Lunar) for 1411 men and 960 women, aged 20-93 years, from the Geelong Osteoporosis Study, a population-based study in Australia. Sex-stratified means and standard deviations for DXA-derived ALM/BMI were generated for each age-decade, and cutpoints equivalent to T-scores of - 2.0 were derived using reference data for 374 men and 308 women aged 20-39 years. Mean ALM/BMI values were greater for men than women, and decreased with age in both sexes. Cutpoints for ALM/BMI corresponding to T-scores of - 2.0 were 0.827 m² for men and 0.518 m² for women. For individuals aged 65+ years, cross-classification of low lean mass according to FNIH criteria (ALM/BMI < 0.789 m² men and < 0.512 m² women) in comparison with our cutpoints for ALM/BMI showed overall agreement of 94.6% for men and 99.0% for women (κ 0.73 and 0.89, respectively). We report good agreement for low ALM indexed to BMI, particularly for women, between classifications based on recommendations from the FNIH Sarcopenia Project for identifying clinically significant weakness, with low values identified within our population distribution of ALM/BMI.

Insulin resistance since early adulthood and appendicular lean mass in middle-aged adults without diabetes: 20 years of the CARDIA study

AIMS

To determine the association between 20-year trajectories in insulin resistance (IR) since young adulthood and appendicular lean mass (ALM) at middle-age in adults without diabetes.

METHODS

A prospective cohort study was designed among young and middle-aged US men (n = 925) and women (n = 1193). Fasting serum glucose and insulin were measured five times in 1985-2005. IR was determined using the homeostasis model assessment (HOMA). ALM was measured in 2005 and ALM adjusted for BMI (ALM/BMI) was the outcome. Sex-specific analyses were performed.

RESULTS

Three HOMA-IR trajectories were identified. Compared to the low-stable group, the adjusted ALM/BMI difference was -0.041 (95% CI: -0.060 to -0.022) and -0.114 (-0.141 to -0.086) in men, and -0.052 (-0.065 to -0.039) and -0.043 (-0.063 to -0.023) in women, respectively, for the medium-increase and high-increase groups. Further adjusting for the treadmill test duration attenuated these estimates to -0.022 (-0.040 to -0.004) and -0.061 (-0.089 to -0.034) in men and -0.026 (-0.038 to -0.014) and -0.007 (-0.026 to 0.012) in women.

CONCLUSIONS

Compared to the low-stable insulin resistance trajectory between early and middle adulthood, the high-increase trajectory was associated with lower ALM/BMI in middle-aged men, but not women, without diabetes, after adjusting for cardiorespiratory fitness.

A cross-sectional study on sarcopenia using different methods: reference values for healthy Saudi young men

BACKGROUND

The aim of this study was to determine reference values for sarcopenia indices using different methods in healthy Saudi young men.

METHODS

Participants included 232 Saudi men aged between 20 and 35 years. The study measured anthropometric indices, blood pressure, hand grip strength, and lean muscle mass using dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis (BIA) was performed using Inbody 770 and Tanita 980 devices.

RESULTS

Using DXA, the mean value of appendicular lean mass divided by the height squared (ALM/ht2) was found to be 8.97 ± 1.23 kg/m2; hand grip strength measured 42.8 ± 7.6 kg. While the differences between DXA and BIA (Tanita) were significant for all parameters, the differences between DXA and Inbody values were significant only for ALM parameters. Inbody sensitivity and specificity values were 73% and 95.9%, respectively. The kappa (P = 0.80) and p values (P < 0.001) showed good agreement between Inbody and DXA, whereas Tanita sensitivity and specificity values were 54.2% and 98.3%, respectively. Bland-Altman plots for differences in lean mass values between Tanita, Inbody, and DXA methods showed very high bias for Tanita and DXA, with significant differences (P < 0.001).

CONCLUSIONS

The cut-off values for sarcopenia indices for Saudi young men are different from those of other ethnicities. The use of tailored cut-off reference values instead of a general cut-off for BIA devices is recommended.

Measurement of muscle mass in sarcopenia: from imaging to biochemical markers

Sarcopenia encompasses the loss of muscle mass and strength/function during aging. Several methods are available for the estimation of muscle or lean body mass. Popular assessment tools include body imaging techniques (e.g., magnetic resonance imaging, computed tomography, dual X-ray absorptiometry, ultrasonography), bioelectric impedance analysis, anthropometric parameters (e.g., calf circumference, mid-arm muscle circumference), and biochemical markers (total or partial body potassium, serum and urinary creatinine, deuterated creatine dilution method). The heterogeneity of the populations to be evaluated as well as the setting in which sarcopenia is investigated impacts the definition of "gold standard" assessment techniques. The aim of this article is to critically review available methods for muscle mass estimation, highlighting strengths and weaknesses of each of them as well as their proposed field of application.

No effect of anti-inflammatory medication on postprandial and postexercise muscle protein synthesis in elderly men with slightly elevated systemic inflammation

BACKGROUND

Based on circulating C-reactive protein (CRP) levels, some individuals develop slightly increased inflammation as they age. In elderly inflamed rats, the muscle response to protein feeding is impaired, whereas it can be maintained by treatment with non-steroidal anti-inflammatory drugs (NSAIDs). It is unknown whether this applies to elderly humans with increased inflammation. Thus, the muscle response to whey protein bolus ingestion with and without acute resistance exercise was compared between healthy elderly individuals and elderly individuals with slightly increased inflammation±NSAID treatment.

METHODS

Twenty-four elderly men (>60years) were recruited. Of those, 14 displayed a slightly increased systemic inflammation (CRP>2mg/l) and were randomly assigned to NSAID (Ibuprofen 1800mg/day) or placebo treatment for 1week. The remaining 10 elderly individuals served as healthy controls (CRP<1mg/l). The muscle protein synthetic response was measured as the fractional synthetic rate (FSR) and p70S6K phosphorylation-to-total protein ratio.

RESULTS

The basal myofibrillar FSR and the myofibrillar FSR responses to whey protein bolus ingestion with and without acute resistance exercise were maintained in inflamed elderly compared to healthy controls (p>0.05) and so was p70S6K phosphorylation. Moreover, NSAID treatment did not significantly improve the myofibrillar and connective tissue FSR responses or reduce the plasma CRP level in inflamed, elderly individuals (p>0.05).

CONCLUSION

A slight increase in systemic inflammation does not affect the basal myofibrillar FSR or the myofibrillar FSR responses, which suggests that elderly individuals with slightly increased inflammation can benefit from protein ingestion and resistance exercise to stimulate muscle protein anabolism. Moreover, the NSAID treatment did not significantly affect the myofibrillar or connective tissue FSR responses to protein ingestion and acute resistance exercise.

Variations in fat mass contribution to bone mineral density by gender, age, and body mass index: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011

The relationship of body composition and bone mineral density is complex and controversial. When classifying Korean population based on gender, age, and body mass index, fat mass had varying contributions to bone mineral density.

INTRODUCTION

The relationship between body composition and bone mineral density (BMD) is complex, and it is uncertain how components of body mass variably affect BMD.

METHODS

This cross-sectional observational study was performed in subjects ≥20 years based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2011. Among 17,583 subjects, the mean ages were 49.1 ± 16.0 years (M, n = 7495) and 49.3 ± 16.3 years (F, n = 10,088). Subjects were divided into age groups, either <50 or ≥50 years for males, or menopausal state, either premenopausal or postmenopausal, for females. A further classification used BMI, either <25 or ≥25 kg/m(2). Anthropometric and body composition parameters were compared and evaluated to look for correlations with BMD. Further, appendicular lean mass (ALM), fat mass (FM), fat percentage (FP), and waist circumference (WC) were included for multivariate analysis with BMD, controlling for covariates in each age group and BMI subgroup.

RESULTS

Anthropometric and body composition parameters significantly correlated with BMD in all age groups for both genders. After adjusting for covariates, ALM strongly affected BMD in all age groups for both genders. FM, FP, and WC significantly affected BMD in both age groups of women and in older men, but they did not affect BMD in younger men. Fat indices positively affected BMD of all sites in all non-obese women and in non-obese older men. However, little contribution was found in obese subgroups of both genders and in non-obese younger men.

CONCLUSION

Considering different weights of covariates, ALM strongly contributed to BMD in all gender, age, and BMI groups. On the other hand, fat indices positively affected BMD of both age groups in women and older men with normal BMI, but they showed little contribution to BMD within the same age groups with high BMI or any BMI subgroups of younger men.

Adherence to a Mediterranean-Style Diet and Appendicular Lean Mass in Community-Dwelling Older People: Results From the Berlin Aging Study II

BACKGROUND

Selected nutrients or food groups have often been studied with regard to long-term mortality and cardiovascular disease, whereas the relation between diet quality and appendicular lean mass (ALM) has rarely been researched.

OBJECTIVE

The aim of this study was to explore the association between a Mediterranean-style diet and ALM in community-dwelling older people.

METHODS

Cross-sectional data from the Berlin Aging Study II were available for 1,509 participants (51% women, 68.2±3.7 years). Nutrient intake was assessed using the European Prospective Investigation into Cancer and Nutrition Food Frequency Questionnaire. Adherence to a Mediterranean-style diet was evaluated with the modified Mediterranean-type diet score (mMedTypeDiet). ALM was determined by dual-energy X-ray absorptiometry and related to body mass index (ALM/BMI). A general linear regression model was carried out to assess the association between mMedTypeDiet score groups and ALM/BMI.

RESULTS

ALM/BMI was higher in women with a higher adherence to the mMedTypeDiet (0.64±0.1 vs 0.62±0.1 and 0.61±0.1 in low and medium adherence, retrospectively, p = .004). In the risk factor-adjusted general linear regression analysis, a higher adherence to the mMedTypeDiet was associated with higher ALM/BMI in women and better ALM/fat mass ratio when compared to a medium and a low diet quality. No significant associations were seen in men.

CONCLUSIONS

Higher adherence to a Mediterranean-style diet was associated with a positive effect on ALM/BMI in women.

Sarcopenia and body composition in diabetic Charcot osteoarthropathy

BACKGROUND

Treatment of Charcot osteoarthropathy (COA) requires restricted walking and offloading for several months, which lead to fat re-distribution and increased sarcopenia.

OBJECTIVES/AIM

To investigate whether subjects with COA have an altered body composition compared to controls.

METHODS

Cross-sectional case-control study of people with diabetes with acute or chronic Charcot osteoarthropathy, matched with otherwise healthy people with diabetes. A total of 49 subjects (distribution ~1:1) had a total body DXA-scanning, measuring appendicular lean mass, android/gynoid and truncal/total body fat distribution ratios.

RESULTS

Sarcopenia frequency was higher in the total population with diabetes overall (9-40%), compared to normal materials. Using two different models for correlating appendicular lean mass to sarcopenia, there were no differences in sarcopenia-rates between the groups (P=0.413 and 0.948 respectively). There was no significant difference in lean tissue mass between the affected and the unaffected leg in the immobilised subject group (P=0.830). The average fat percentage was (29.4-37.7%) in the population with diabetes, compared to a matching background population (24.5-31.9%), whereas there were no significant differences found between the groups (P=0.065). Neither truncal/total fat percent nor android/gynoid fat percent ratios showed differences between the groups.

CONCLUSION

To our knowledge, this is the first published dataset investigating body composition in subjects with Charcot osteoarthropathy. The study population of diabetics were more fat and sarcopenic than normal subjects, whereas no statistically significant impact of Charcot osteoarthropathy was found.